Super Mario goes theremine

The sound from the theremin is split into its frequency and amplitude components in real time, which are then mapped to values in a linear scale representing the X and Y axis. Pitch becomes horizontal control, and Volume becomes vertical control.
The X and Y scales are then cut up into different zones. In this case, Left; Right and dead zones for the horizontal, and a single trigger and dead zone for the vertical.

The trigger zones are then mapped onto a virtual joystick hooked into an emulator.